Clearing the 12th floor

(From Mc's Perspective)

12th floor,

After arriving on the twelfth floor, I looked around for a moment. There is overwhelming silence around the area. I don't know why this feels a little creepy. But I'm on guard with my perception. I try to notice any subtle changes around here. 

After a couple of seconds, I heard some noise,

Hearing that sound makes my expression dignified. Usually, Monsters appear out of thin air in front of me. "What is happening now?" I mumbled under my breath. This pattern is something new to me. So, I didn't let down my guard.

Suddenly, 

I heard something coming towards me. I held my black sword in a vertical position to attack it.  Using my operation, I saw something unbelievable. This twelfth floor is quite visible, after a couple of seconds the thing becomes visible to naked eye.